Male coronavirus survivors are being urged to give blood because of evidence that men produce more antibodies, which could make their plasma a more valuable treatment.
The research, by NHS Blood and Transplant (NHSBT), suggests men may hold the key in the battle against the virus.
Health chiefs are urging men who have had Covid-19 to come forward and donate blood as part of a national trial to see whether donations can boost the survival of the sickest patients.
Their research shows that 43 percent of male donors had blood plasma rich enough in antibodies, compared with 29 percent of women.
Antibodies are produced when the body's immune system tries to fight off a virus.
Men with Covid-19 tend to produce more antibodies than women with the virus because men are more likely to become seriously ill.
The trial is assessing whether plasma donations from recovered patients can be transfused into patients who are struggling to develop their own immune response.
Professor David Roberts, associate director for blood donation at NHSBT, said: "We'd still like to hear from anybody who had coronavirus or the symptoms. More plasma donors are needed.
"But we'd especially want to hear from men. We test every plasma donation and men have higher antibody levels, which means we're more likely to be able to use their plasma to save lives.
"Initially, your immune system will try and fight off a virus with white blood cells. If you become more ill, your immune system needs to produce more antibodies that neutralise or kill the virus.
"Our studies, and many others around the world, show men with Covid-19 are more likely to become seriously ill than women. This makes them better plasma donors once they have recovered."
Last week it was announced that anyone who tests positive for Covid-19 through the national testing program will be asked to join a blood plasma trial.
NHSBT said people confirmed with the virus through Test and Trace will receive a text message three weeks after their result to see whether they are willing to donate plasma.
If the trial is successful, being treated with convalescent plasma could become widespread practice in hospitals.
convalescent[ˌkɑːnvəˈlesnt]: adj. 康复的；恢复期的